Syringes for use in medical applications typically include a syringe barrel, a plunger reciprocally movable in the syringe barrel, and a gasket attached to a distal end of the plunger.
The gasket to be used for the syringes is required to have gas tightness and low-friction slidability. The gas tightness means that liquid drug is prevented from leaking outside during use and foreign matter is prevented from intruding from the outside. The low-friction slidability means that, when the syringe is used, a user can properly move the gasket by manipulating the plunger by one hand.
The prior-art syringes ensure the low-friction slidability and the gas tightness with a silicone oil applied in the syringe barrel, but some liquid drugs are adversely influenced by the silicone. Therefore, it is desirable not to apply the silicone to the syringe barrel.
From this viewpoint, a product called laminated gasket is often used, which includes a rubber gasket body having a surface laminated with a film having excellent slidability (e.g., a gasket laminated with a fluororesin film).